A family history of diabetes mellitus is associated with poor glycemic control and increased metabolic risks among people with diabetes: data from the National Health and Nutrition Examination Survey 1999-2004.

BACKGROUND: Several lines of evidence from studies involving both general and non-diabetic populations have shown that a family history of diabetes was associated with an increased risk for cardiovascular diseases and metabolic alterations. However, little is known about the relationship of a family history of diabetes to glycemic control and metabolic risks among people with diabetes.
METHODS: We conducted a cross-section study of 946 diabetic adults from the National Health and Nutrition Examination Survey between 1999 and 2004. Familial risk of diabetes was classified as average, moderate, or high. Logistic regression analyses were conducted to determine the association between familial risk of diabetes and poor glycemic control, as defined by A1C > or = 8%. According to stratified levels of familial risk of diabetes, adjusted means of various metabolic risks, including A1C, BMI, lipid profiles, and C-reactive protein, were obtained by using multiple linear regression.
RESULTS: Independent of basic demographics, health-related behaviors, use of anti-diabetic medications, diabetes duration, cardiovascular co-morbidities, and various metabolic risks, the odds ratio of poor glycemic control comparing participants with a high familial risk of diabetes to those with an average risk was 1.91 (95% confidence interval 1.02-3.58). In the multivariate analysis, the adjusted means of A1C in participants with high, moderate, and averaged familial risk of diabetes were 7.75%, 7.45%, and 7.25%, respectively (p for trend 0.036). Participants with a high familial risk of diabetes also had higher triglycerides and body mass index (p for trend 0.042 and 0.02, respectively).
CONCLUSION: Diabetic adults with a higher familial risk of diabetes have a worse glycemic control, higher BMI, and higher triglycerides. Obtaining family history of the disease is crucial in identifying and targeting high risk diabetic patients who may require more stringent lifestyle changes as well as pharmaceutical intervention.